title: Calcium pumps: why so many?
abstract: Ca(2+)-ATPases (pumps) are key to the regulation of Ca(2+) in eukaryotic cells: nine are known today, belonging to three multigene families. The three endo(sarco)plasmic reticulum (SERCA) and the four plasma membrane (PMCA) pumps have been known for decades, the two Secretory Pathway Ca(2+) ATPase (SPCA) pumps have only become known recently. The number of pump isoforms is further increased by alternative splicing processes. The three pump types share the basic features of the catalytic mechanism, but differ in a number of properties related to tissue distribution, regulation, and role in the cellular homeostasis of Ca(2+). The molecular understanding of the function of all pumps has received great impetus from the solution of the three-dimensional (3D) structure of one of them, the SERCA pump. This landmark structural advance has been accompanied by the emergence and rapid expansion of the area of pump malfunction. Most of the pump defects described so far are genetic and produce subtler, often tissue and isoform specific, disturbances that affect individual components of the Ca(2+)-controlling and/or processing machinery, compellingly indicating a specialized role for each Ca(2+) pump type and/or isoform.
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro Padova, Italy. marisa.brini@unipd.it
authors.forename: Marisa
authors.initials: M
authors.lastname: Brini
authors.forename: Tito
authors.initials: T
authors.lastname: Calì
authors.forename: Denis
authors.initials: D
authors.lastname: Ottolini
authors.forename: Ernesto
authors.initials: E
authors.lastname: Carafoli
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007527:Isoenzymes / Q000502:physiology; D008958:Models, Molecular; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D011499:Protein Processing, Post-Translational; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000737:chemistry / Q000235:genetics / Q000502:physiology
chemical_list: D007527:Isoenzymes; D053499:Plasma Membrane Calcium-Transporting ATPases; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C403624:ATP2C1 protein, human; D000252:Calcium-Transporting ATPases; D002118:Calcium